The importance of providing means for adjusting the liquid cutoff level in a water closet or toilet flush tank, in order to save water, has long been recognized, and various mechanisms designed to accomplish this effect are known including the following U.S. Pat. Nos.: 1,177,963 Peterson Apr. 4, 1916, 3,298,231 Zukley Jan. 17, 1967, 3,331,307 Walters July 18, 1967, 3,385,317 Yankers May 28, 1968.
None of the above patents disclose the use of a buoyant casing or cover applied to the usual ball-type float for the water control valve in order to reduce the water level in the tank at which the water cutoff takes place as compared to the level using the uncovered float.